Mild, moisturizing cleansing compositions

ABSTRACT

Compositions used for cleansing hair and skin based on the combination of a sulfosuccinate surfactant and an amphoteric surfactant are described that are very mild but do not compromise in-use properties and economy. A route to solve the intrinsic instability of such aqueous compositions in storage has been developed based on the use of sulfosuccinic acid or a salt of sulfosuccinic acid present in an amount of at least about 4% based on the weight of the sulfosuccinate surfactant.

FIELD OF INVENTION

The present invention is directed at mild cleansing compositions thathave desirable in-use properties such as lather, provide excellentmoisturizing and conditioning benefits to hair and skin and are stablein storage.

BACKGROUND OF INVENTION

Cleansing compositions that are mild to the hair and skin and areperceived to provide the sensory attributes that consumers associatewith healthy, moisturized hair and skin have become increasingly popularin recent years.

Although various mild surfactant systems have been proposed as the basisof such cleansing compositions there is generally a trade-off betweenthe mildness of a composition and its ability to produce a rich abundantlather. Consequently when using mild surfactants, formulators oftenincrease the total surfactant content to overcome this latherdeficiency. Not only does this adversely affect the economics of thecomposition but this can also reduce the mildness of the compositionsince the ability of a surfactant to interact with the proteins presentin hair and skin depends on the total surfactant concentration inaddition to other factors. Furthermore, high concentrations ofsurfactants can also interfere with the efficient delivery of insolublehair and skin conditioning agents that are desirable to incorporate inmoisturizing shampoo compositions.

Thus there remains a need for surfactant compositions that are mild tohair and skin and yet are efficient in terms of producing a rich,abundant lather without the need to use excessive levels of surfactantin the composition and which are highly compatible with insoluble hairconditioning agents.

While studying a variety of mild cleansing compositions, it has beenfound that binary mixtures of certain sulfosuccinate surfactants andamphoteric surfactants used alone or in further combination with alkylethoxy sulfates and other surfactants can provide highly efficient andmild shampoo and skin cleansing bases. However, these bases had highlyvariable and unpredictable storage stability. Some combinations becamevery viscous, even gelling during storage and were unacceptable toconsumers while others having what appeared to be the same “nominal”composition did not.

Extensive study and chemical analysis indicated that it was theinteraction of hydrolysis products of the sulfosuccinate surfactant withthe amphoteric surfactant that was responsible for the anomalousthickening in storage. Furthermore it was surprisingly found that thelevel of sulfosuccinic acid or its simple salt that was present in thecomposition had a pronounced and critical effect on storage stability,especially under high temperature storage conditions. These findingsprovided the basis for making practical shampoo and skin cleansingcompositions that employ a sulfosuccinate surfactant in combination withan amphoteric surfactant. These combinations have the advantage ofproviding very mild compositions that do not compromise lather, areefficient and economical and are highly compatible with hair and skinconditioning agents.

These and other advantages of the compositions disclosed herein willbecome clear from the description of the invention.

The following patents and publications have been considered:

WO93/25650 discloses highly concentrated (30-90%) surfactantconcentrates that include an alkyl polyglycoside and an effective amountof a viscosity-adjusting agent selected from the group consisting ofinorganic and organic electrolytes. Carboxylic acids and their salts arementioned as organic electrolytes.

U.S. Pat. No. 4,668,422 describes compositions based onalkylpolyglycosides and amphoteric surfactants with optional smallamounts of anionic surfactant. Sodium chloride and ammonium chloride aredisclosed as viscosifying agents, i.e., materials that increase theviscosity of the composition.

U.S. Pat. No. 4,839,098 discloses a liquid dishwashing detergentconsisting essentially of alkyl glucoside and dialkylsulfosuccinate.Ammonium chloride is disclosed as a viscosity regulator.

U.S. Pat. No. 6,165,454 discloses a low energy method for making haircare products including an anionic surfactant, a water insolublesilicone and an acrylic stabilizing agent.

U.S. Pat. No. 6,306,805 discloses surfactant compositions that include acationic surfactant, an anionic surfactant and a bridging surfactant.

The present invention seeks improvements over deficiencies in the knownart. Among the one or more problems addressed include storageinstability.

SUMMARY OF THE INVENTION

The subject invention provides a composition that is mild to hair andskin, has excellent lather and is highly efficient in terms of therelatively low total surfactant content required.

More specifically, the mild aqueous composition which is highly suitablefor cleansing hair and skin includes:

-   -   i) from about 1% to about 20% of a sulfosuccinate surfactant,    -   ii) from about 1% to about 20% of an amphoteric surfactant, and    -   iii) a sulfosuccinic acid or a salt of a sulfosuccinic acid,    -   wherein the sulfosuccinic acid or the salt of sulfosuccinic acid        is present in an amount of at least about 4% based on the weight        of the sulfosuccinate surfactant.

In a second preferred embodiment of the invention, the binarysulfosuccinate/amphoteric surfactant mixture is further combined with anadditional anionic surfactant or surfactants, which preferably containsat least one surfactant that is an alkyl ethoxy sulfate.

DETAILED DESCRIPTION OF THE INVENTION

As used herein % or wt. % refers to percent by weight of an ingredientas compared to the total weight of the composition or component, that isbeing discussed.

Except in the operating and comparative examples, or where otherwiseexplicitly indicated, all numbers in this description indicating amountsof material or conditions of reaction, physical properties of materialsand/or use are to be understood as modified by the word “about.” Allamounts are by weight of the final composition, unless otherwisespecified.

It should be noted that in specifying any range of concentration, anyparticular upper concentration can be associated with any particularlower concentration.

For the avoidance of doubt the word “comprising” is intended to mean“including” but not necessarily “consisting of” or “composed of.” Inother words, the listed steps or options need not be exhaustive.

The present invention relates to mild compositions suitable forcleansing human hair and skin. The composition includes a surfactantsystem, sulfosuccinic acid or its salt and various optional hair and/orskin care additives, and adjuncts. These components are discussed indetail below.

Surfactant System

The surfactant system is composed of the combination of two essentialtypes of surfactants: one is a sulfosuccinate anionic surfactant and theother is an amphoteric surfactant.

The sulfosuccinate anionic surfactant is preferably the half esterhaving the general formula:

where R is a straight or branched chain alkyl or alkenyl group having 10to 22 carbon atoms, X is a number that represents the average degree ofethoxylation and can range from 0 to about 5, preferably from 0 to about4, and most preferably from about 2 to about 3.5, and M and M′ aremonovalent cations which can be the same or different from each other.Preferred cations are alkali metal ions such as sodium or potassium,ammonium ions, or alkanolammonium ions such as monoethanolammonium ortriethanolammonium ions.

Preferred sulfosuccinate surfactants include C₁₀-C₁₄ sulfosuccinate, andC₁₀-C₁₄. ethoxy (1-5) sulfosuccinate. Laureth-3 sulfosuccinate is anespecially preferred sulfosuccinate surfactant.

The level of sulfosuccinate surfactant present in the composition can bein the range from about 1% to about 20% by weight of the composition,preferably about 1% to about 10%, and most preferably from about 1.5% toabout 7% of the composition.

The second essential component of the surfactant system is an amphotericsurfactant.

An especially preferred amphoteric surfactant is a betaine surfactanthaving the following general chemical formula:

where R1 is either an alkyl or an alkyl amidoalkyl group. The alkylgroup in either case can be a branched or a straight chain alkyl grouphaving 8-18 carbon atoms, preferably 10-16 carbon atoms and mostpreferably 10-14 carbon atoms. Available betaines include oleyl betaine,caprylamidopropyl betaine, lauramidopropyl betaine,isostearylamidopropyl betaine, and coco imidoazolinium betaine.

Particularly preferred betaines are lauryl or coco betaine, and laurylor coco amidopropyl betaine. The term “lauryl” refers to predominantly afatty acid of C₁₂ chainlength while coco refers to a mixture of C₁₂ andC₁₄ chainlength fatty acids.

A second type of suitable amphoteric surfactant is an hydroxysultaine(CTFA name for a sulfobetaine having the hydroxypropyl sulfonate group)which are generally formed from the reaction of a tertiary amine withepichlorohydrin and a bisulfite. Their general formula is:

where R1 is either an alkyl or an alkyl amidoalkyl group. The alkylgroup in either case can be a branched or a straight chain alkyl grouphaving 8-18 carbon atoms, preferably 10-16 carbon atoms and mostpreferably 10-14 carbon atoms. Commercially available sultaines include:lauryl hydroxy sultaine, tallowamidopropyl hydroxy sultaine,erucamidopropyl hydroxy sultaine, and alkylether hydroxypropyl sultaine.

Preferred hydroxysultaines are coco and laurylamidopropyl hydroxysultaine and coco amidopropyl hydroxysultaine.

Another class of amphoteric surfactants is formed by the reaction ofimidazoline with chloroacetic acid. This class includes the fattyamphoacetates and fatty amphodiacetates having the general formula shownbelow. These materials were formally known as amphoglycinates andamphocarboxyglycinates respectively.

where R is a straight or a branched chain alkyl chain having 10 to 16carbon atoms and R2 is either H or a —CH2—COOH.

Preferred amphoacetates are coco and lauro amphoacetate and preferredamphodiacetates are lauro and coco amphodiacetate.

Other less preferred amphoteric surfactants include C₁₀-C₁₆ fattyamphocarboxy propionates and C₁₀-C₁₆ fatty amphopropionates.

Another class of amphoteric surfactant is fatty amine oxide such aslauryl dimethyl amine oxide. These surfactants have been classified byvarious workers as “nonionic” surfactants, “cationic” surfactants, and“amphoteric” surfactants. The N-oxide group is a weak base having apk_(b) of about 9. Thus, at pH of 5 about 50% of the molecules exist asthe positive N⁺—OH species, while at pH 6.5 only about 3% exists as thepositively charged species. For the purposes of the present invention,fatty amine oxides are classified as amphoteric surfactants

The level of amphoteric surfactant present in the composition can be inthe range from about 1% to about 20% by weight of the composition,preferably about 1% to about 10%, and most preferably from about 1.5% toabout 5.5% of the composition.

The ratio of sulfosuccinate surfactant to amphoteric surfactant ispreferably in the range from about 2:1 to about 1:2, more preferablyfrom about 1.5:1 to about 1:1.25, and most preferably from about 1.5:1to about 1:1.

A variety of optional surfactants which are suitable for cleansing humanhair and skin can also be included in the composition provided they donot excessively compromise the mildness of the composition. Theseinclude anionic surfactants such as acyl isethionates, alkyl sulfates,alkyl ethoxy sulfates, fatty sarcosinates, alkyl taurates and variousamino acid based amido carboxylates; non-ionic surfactants such asalcohol ethoxylates, fatty amides, alkyl (poly)saccharides, and alkylglucamides; and cationic surfactants such as long chain fatty amines andlong chain fatty ethoxylated amines.

A particularly preferred optional surfactant is an alkyl ethoxy sulfatehaving the general formulaR3-(O—CH₂—CH₂—)_(x)—O SO₃ Mwherein R3 is an alkyl group having a straight or branched alkyl chain.The alkyl group can contain 8-20 carbon atoms, preferably 10-18 carbonatoms and most preferably 12-15 carbon atoms. “X” represents the averageethylene oxide content per surfactant molecule and can in principle bein the range from about 0.5 to about 10, preferably from about 0.5 toabout 5 and most preferably between about 0.5 and about 3.5.

“M” represents a cation, preferably a monovalent cation, and mostpreferably sodium, ammonium or alkanolammonium ion.

The alkyl ethoxy sulfate can be present is the composition in an amountranging from about 1% to about 25%, preferably about 4% to about 12%,and most preferably about 4% to about 8% based on the total weight ofthe composition.

The total surfactant content of the compositions of the instantinvention can range from about 1 to about 30% by weight. However, sincethe compositions are directed at end-use hair and skin cleansing byconsumers and not as concentrates, the surfactant content is preferablyabout 3 to about 25% and most preferably about 4% to about 15%.

Sulfosuccinic Acid or Sulfosuccinate Salt

It has been surprisingly found that sulfosuccinic acid or the sodium,potassium, ammonium, or alkanolamonnium salt of sulfosuccinic acidgreatly improves the long term stability of compositions that combine ansulfosuccinate surfactant with an amphoteric surfactant. Weight ofsulfosuccinic acid is conveniently expressed as the ratio ofsulfosuccinic acid (or the stoichiometric equivalent of sulfosuccinicacid in the case of its salt) to that of the total weight of thesulfosuccinate surfactant times 100. This number is designated herein asthe “% (or “percent”) sulfosuccinic acid relative to the total weight ofthe sulfosuccinate surfactant present. The % sulfosuccinic acid shouldbe at least about 4%, preferably at least about 5% and most preferablyat least about 6% relative to the sulfosuccinate surfactant.

Although the addition of sulfosuccinate or its salt in the compositioncan have a slight effect in increasing the initial viscosity of thecompositions, the inventors have surprisingly found sulfosuccinate orits salt has a much larger than expected effect in preventing anincrease in the viscosity of the composition after storage, especiallystorage at elevated temperatures. Thus, the sulfosuccinate acts as astorage stabilizing agent and maintains the viscosity of the compositionapproximately at its initial value before storage. By the term“maintains the viscosity at its initial value” is meant that theviscosity of the composition after storage is not obviously different toan untrained observer in the course of normal use of the composition. Toachieve this level of viscosity “maintenance” generally requires thatthe viscosity after storage does not vary (i.e., increase) by more thanabout 75% of its initial value, and preferably is within about 65% ofits initial value. Thus, the level of sulfosuccinic acid is chosen toachieve this viscosity maintenance. This level depends on the specificcomposition employed but has been found to be at least about 4% relativeto the sulfosuccinate surfactant.

The term “initial viscosity” refers to the viscosity of the compositionafter it has been prepared and stored at room temperature (approximately25-27° C.) for a sufficient amount of time to allow equilibration.Generally, the sample is allowed to equilibrate overnight (15-24 hrs)before the initial viscosity is recorded.

As is well known, it is convenient to use as one indicator of long termstorage stability, accelerated storage testing where the testcomposition is exposed to a higher temperature. In the present contextit is preferred that the composition maintain its viscosity afterstorage at 49° C. for a minimum of about 4 weeks of storage and mostpreferably for a minimum of about 11 weeks of storage.

From the above discussion, it should be clear that the sulfosuccinicacid or salt is not acting in the mixed sulfosuccinate-amphotericcompositions of the present invention as a traditional viscosityregulator since it has a marginal effect on the viscosity of thecomposition in the absence of storage.

There are two main routes for the introduction of the sulfosuccinic acid(or sulfosuccinic acid salt). The first is as a component of thecommercial sulfosuccinate surfactant, either as residual reactant or asa hydrolysis product. The second is by separate and direct addition ofthe sulfosuccinic acid or its salt to the composition. Of course acombination of these two addition routes can also be employed to achievethe viscosity maintenance level described above. Regardless of how thesulfosuccinic acid is introduced, its total level expressed as a weight% of sulfosuccinic acid relative to the total weight of thesulfosuccinate surfactant should exceed the critical value set forthabove.

Optional Ingredients

Buffering Agents

The pH of the composition desirably ranges from about 5 to about 7,preferably between about 6 and about 6.5 and most preferably betweenabout 6.1 and about 6.4.

It is also preferable to achieve an adequate acid buffer capacity toresist pH changes, as this has been found to improve the physicalstorage stability of the composition.

The acid buffer capacity is defined as the number of moles of acid(e.g., protons or hydronium ions) that can be added to one liter of thecomposition to result in a drop in pH by 1 pH unit. The acid buffercapacity can be measured by titration of the test composition (generallya 10-fold dilution) with a standard solution of a strong acid such asHCl using a pH electrode. In practice, it has been found the acid buffercapacity of the composition be at least about 0.01 moles hydrodium ion,preferably at least about 0.02 moles, and most preferably at least about0.03 moles per liter of composition.

A variety of acid/base pairs can be used as the buffer system as is wellknown in the art. Particularly suitable buffers are citric acidneutralized with sodium or ammonium hydroxide and polyacrylic acidneutralized with sodium or ammonium hydroxide.

Conditioning Agents

The compositions of this invention can also contain one or moreconditioning agents selected from silicone conditioning agents andnon-silicone conditioning agents.

Conditioning agents present in the compositions in droplet orparticulate form, that can be liquid, semi-solid or solid in nature, solong as they are substantially uniformly dispersed in the fullyformulated product. Any droplets of oily conditioning agent arepreferably present as either liquid or semi-solid droplets, morepreferably as liquid droplets.

i) Silicone Conditioning Agents

The compositions of the present invention can further include a siliconeconditioning agent at concentrations effective to provide hair and skinconditioning benefits. Such concentrations range from about 0.01% toabout 5%, preferably from about 0.1% to about 5%, and most preferablyfrom about 0.1% to about 3%, by weight of the shampoo compositions.

The silicone conditioning agents are preferably water insoluble andnon-volatile silicones but water soluble and volatile silicones can alsobe utilized. Typically the silicone will be intermixed in thecomposition so as to be in the form of a separate, discontinuous phaseof dispersed, insoluble particles, also referred to as droplets. Thesedroplets are typically suspended with an optional suspending agentdescribed hereinafter. The silicone conditioning agent phase maycomprise a silicone fluid conditioning agent and can also comprise otheringredients, such as a silicone resin to improve silicone fluiddeposition efficiency or enhance glossiness (especially when employinghigh refractive index silicones).

Suitable silicones include polydiorganosiloxanes, in particularpolydimethylsiloxanes that have the CTFA designation dimethicone. Alsosuitable for use in compositions of the invention (particularly shampoosand conditioners) are polydimethyl siloxanes having hydroxyl end groups,which have the CTFA designation dimethiconol.

Also suitable for use in compositions of the invention are silicone gumsor resins having a slight degree of cross-linking, as are described forexample in WO 96/31188. In the case of hair applications, thesematerials can impart body, volume and stylability to hair, as well asgood wet and dry conditioning. Examples of such materials are thoseoffered by General Electric as GE SS4230 and GE SS4267. Commerciallyavailable silicone resins will generally be supplied in a dissolved formin a low viscosity volatile or nonvolatile silicone fluid but they canalso be used as preformed emulsions.

Another category of nonvolatile, insoluble silicone fluid conditioningagent is the high refractive index silicones, having a refractive indexof at least about 1.46, preferably at least about 1.48, more preferablyat least about 1.52, most preferably at least about 1.55. The refractiveindex of the polysiloxane fluid will generally be less than about 1.70,typically less than about 1.60. In this context, polysiloxane “fluid”includes oils as well as gums. The high refractive index polysiloxanefluids contain a sufficient amount of aryl-containing substituents toincrease the refractive index to the desired level, which is describedabove.

The viscosity of the emulsified silicone itself (not the emulsion or thefinal hair or skin conditioning composition) is typically at least10,000 cst, preferably at least 60,000 cst, most preferably at least500,000 cst, ideally at least 1,000,000 cst. Preferably the viscositydoes not exceed 10,000,000 cst for ease of formulation.

Emulsified silicones for use in the compositions of the invention willtypically have an average silicone droplet size ranging from about 0.1μm to about 100 μm. For shampoo applications a smaller silicone dropletsize is preferable, generally less than 30, preferably less than 20,more preferably less than 10 μm. Conversely, for body wash applicationsa larger droplet size, ranging from about 50 μm, to above 100 μm can beemployed.

Suitable silicone emulsions for use in the invention are alsocommercially available in a pre-emulsified form either as conventionalor as microemulsions. Examples of suitable pre-formed emulsions includeemulsions DC2-1766, DC2-1784, and microemulsions DC2-1865 and DC2-1870,all available from Dow Corning. These are all emulsions/microemulsionsof dimethiconol. Cross-linked silicone gums are also available in apre-emulsified form, which is advantageous for ease of formulation. Apreferred example is the material available from Dow Corning as DCX2-1787, which is an emulsion of cross-linked dimethiconol gum. Afurther preferred example is the material available from Dow Corning asDC X2-1391, which is a microemulsion of cross-linked dimethiconol gum.

It has been reported in WO9953889 that utilizing a combination ofemulsified silicone and microemulsified silicone, in the shampoocomposition can significantly boost the conditioning performance ofsilicone in a surfactant-based shampoo composition. The weight ratio ofemulsified particles of silicone to microemulsified particles ofsilicone suitably ranges from 4:1 to 1:4. Preferably, the ratio ofemulsified particles of silicone to microemulsified particles ofsilicone ranges from 3:1 to 1:3, more preferably from 2:1 to 1:1.

A further preferred class of silicones for inclusion especially inshampoos and conditioners of the invention are amino functionalsilicones. By “amino functional silicone” is meant a silicone containingat least one primary, secondary or tertiary amine group, or a quaternaryammonium group. These will typically have a mole % amine functionalityin the range of from about 0.1 to about 8.0 mole %, preferably fromabout 0.1 to about 5.0 mole %, most preferably from about 0.1 to about2.0 mole %.

Examples of suitable amino functional silicones include polysiloxaneshaving the CTFA designation “amodimethicone”, amino functional siliconestermed “trimethylsilylamodimethicone”, aminofunctional copolymers ofdimethicone and polyalkyleneoxide such as SILSOFT TONE from GeneralElectric Specialty Materials (formally available from OSI), and thequaternary silicone polymers described in EP-A-0 530 974.

The viscosity of the amino functional silicone is not particularlycritical and can suitably range from about 100 to about 500,000 cst.

Also suitable are emulsions of amino functional silicone oils with nonionic and/or cationic surfactant. Pre-formed emulsions of aminofunctional silicone are also available from suppliers of silicone oilssuch as Dow Corning and General Electric. Specific examples includeDC929 Cationic Emulsion, DC939 Cationic Emulsion, and the non-ionicemulsions DC2-7224, DC2-8467, DC2- 8177 and DC2-8154 (all ex DowCorning). Microemulsified amino silicones are also highly suitable.

For shampoo compositions intended for the treatment of “mixed” hair(i.e. greasy roots and dry ends), it is preferred to use a combinationof amino functional and non- amino functional silicone in compositionsof the invention. In such a case, the weight ratio of amino functionalsilicone to non-amino functional silicone will typically range from 1:2to 1:20, preferably 1:3 to 1:20, more preferably 1:3 to 1:8.

Although non-volatile silicones are preferred in the presentcomposition, volatile silicone, which imparts additional attributes suchas gloss to the hair are also suitable. Preferably, the volatilesilicone conditioning agent has an atmospheric pressure boiling pointless than about 220° C. The volatile silicone conditioner is present inan amount of from 0% to about 3%, preferably from about 0.25% to about2.5%, and more preferably from about 0.5% to about 1.0%, based on theoverall weight of the composition. Examples of suitable volatilesilicones nonexclusively include polydimethylsiloxane,polydimethylcyclosiloxane, hexamethyldisiloxane, cyclomethicone fluidssuch as polydimethylcyclosiloxane available commercially from DowCorning Corporation.

Examples of less preferred but suitable water soluble nonvolatilesilicones nonexclusively include cetyl triethylammonium dimethiconecopolyol phthalate, stearalkonium dimethicone copolyol phthalate,dimethicone copolyol and mixtures thereof.

Especially preferred silicones conditioning agents include: dimethiconolemulsion, 60% active from Dow Corning, DC1785 (approximately 1 μmaverage particle size, e.g., D₃₂); dimethiconol emulsion, 40% activefrom Dow Corning, DC 1786 (approximately 0.3 μm average particle size);dimethiconol emulsion, 50% active from Dow Corning, DC 1788 (approximately 0.3 μm average particle size); amodimethicone emulsion,35% active from Dow Corning, DC 939 (approximately 0.3 μm averageparticle size); amodimethicone microemulsion from General Electric, SME253 (approximately 20 nm average particle size); and a siliconegum-amodimethicone blend from Basildon Silicones, PCP 2056S(approximately 1 μm average particle size).

In compositions comprising silicone, it is preferred that a suspendingagent for the silicone also be present. Suitable suspending agents aredescribed separately below.

ii) Non-silicone Oily Conditioning Components

Compositions according to the present invention may also contain adispersed, non-volatile, water-insoluble oily conditioning agent. By“water-insoluble” is meant that the material is not soluble in water(distilled or equivalent) at a concentration of 0.1% (w/w), at 250° C.

Suitably, the D_(3,2) average droplet size of the oily conditioningcomponent is at least 0.4, preferably at least 0.8, and more preferablyat least 1 μm.

Oily or fatty materials or their mixtures are preferred conditioningagents in the compositions of the invention. Suitable oily or fattymaterials are selected from hydrocarbon oils, fatty esters and mixturesthereof.

Hydrocarbon oils include cyclic hydrocarbons, straight chain aliphatichydrocarbons (saturated or unsaturated), and branched chain aliphatichydrocarbons (saturated or unsaturated). Straight chain hydrocarbon oilswill preferably contain from about 12 to about 30 carbon atoms. Branchedchain hydrocarbon oils can and typically may contain higher numbers ofcarbon atoms. Also suitable are polymeric hydrocarbons of alkenylmonomers, such as C2-C6 alkenyl monomers. These polymers can be straightor branched chain polymers. The straight chain polymers will typicallybe relatively short in length, having a total number of carbon atoms asdescribed above for straight chain hydrocarbons in general. The branchedchain polymers can have substantially higher chain length. Specificexamples of suitable hydrocarbon oils include paraffin oil, mineral oil,saturated and unsaturated dodecane, saturated and unsaturated tridecane,saturated and unsaturated tetradecane, saturated and unsaturatedpentadecane, saturated and unsaturated hexadecane, and mixtures thereof.Branched-chain isomers of these compounds, as well as of higher chainlength hydrocarbons, can also be used. Exemplary branched-chain isomersare highly branched saturated or unsaturated alkanes, such as thepermethyl-substituted isomers e.g., the permethyl-substituted isomers ofhexadecane and eicosane, such as 2, 2, 4, 4, 6, 6, 8,8-dimethyl-10-methylundecane and 2, 2, 4, 4, 6,6-dimethyl-8-methyinonane, polybutene, such as the copolymer ofisobutylene and butene. Particularly preferred hydrocarbon oils are thevarious grades of mineral oils, and petrolatum especially for skin careapplications.

Suitable fatty esters are characterized by having at least 10 carbonatoms, and include esters with hydrocarbyl chains derived from fattyacids or alcohols, e.g., monocarboxylic acid esters, polyhydric alcoholesters, and di- and tricarboxylic acid esters.

Monocarboxylic acid esters include esters of alcohols and/or acids ofthe formula R′COOR in which R′ and R independently denote alkyl oralkenyl radicals and the sum of carbon atoms in R′ and R is at least 10,preferably at least 20.

Di- and trialkyl and alkenyl esters of carboxylic acids can also beused. These include, for example, esters of C4-C8 dicarboxylic acidssuch as C1-C22 esters (preferably C1-C6) of succinic acid, glutaricacid, adipic acid, hexanoic acid, heptanoic acid, and octanoic acid.

Polyhydric alcohol esters such as alkylene glycol and polyalkyleneglycol mono, di, and tri esters are also suitable for use in the instantcompositions. Particularly preferred fatty esters are mono-, di- andtriglycerides, more specifically the mono-, di-, and triesters ofglycerol and long chain carboxylic acids such as C1-C22 carboxylicacids. A variety of these types of materials can be obtained fromvegetable and animal fats and oils, such as coconut oil, castor oil,safflower oil, sunflower oil, cottonseed oil, corn oil, olive oil, codliver oil, almond oil, avocado oil, palm oil, sesame oil, peanut oil,lanolin and soybean oil. Synthetic oils include triolein and tristearinglyceryl dilaurate.

Specific examples of preferred materials include cocoa butter, palmstearin, sunflower oil, soyabean oil and coconut oil.

The oily or fatty material is suitably present at a level of from 0.05%to 10%, preferably from about 0.2% to about 5% and more preferably fromabout 0.5% to about 3%.

Cationic Polymer

Cationic polymers are optionally employed to provide enhanced depositionof the non-volatile, water-insoluble silicone as well as conditioningbenefits in their own right. The level of cationic polymer in thecomposition can be in the range from about 0.01 to about 2%, preferablyfrom about 0.1 to about 0.6%, and most preferably from about 0.15 toabout 0.45%.

The cationic conditioning polymer contains cationic nitrogen-containinggroups such as quaternary ammonium or protonated amino groups. Thecationic protonated amines can be primary, secondary, or tertiary amines(preferably secondary or tertiary), depending upon the particularspecies and the selected pH of the shampoo composition. The averagemolecular weight of the cationic conditioning polymers is between about10 million and about 5,000. The polymers also have a cationic chargedensity ranging from about 0.2 meq/gm to about 7 meq/gm.

Any anionic counterions can be use in association with the cationicconditioning polymers so long as the polymers remain soluble or readilydispersible in water, in the composition, or in a coacervate phase ofthe composition, and so long as the counterions are physically andchemically compatible with the essential components of the compositionor do not otherwise unduly impair product performance, stability oraesthetics. Non limiting examples of such counterions include halides(e.g., chlorine, fluorine, bromine, iodine), sulfate and methylsulfate.

The cationic nitrogen-containing moiety of the cationic polymer isgenerally present as a substituent on all, or more typically on some, ofthe monomer units thereof. Thus, the cationic polymer for use in thecomposition includes homopolymers, copolymers, terpolymers, and soforth, of quaternary ammonium or cationic amine-substituted monomerunits, optionally in combination with non-cationic monomers referred toherein as spacer monomers. Non-limiting examples of such polymers aredescribed in the CTFA Cosmetic Ingredient Dictionary, 6th edition,edited by Wenninger, JA and McEwen Jr, GN, (The Cosmetic, Toiletry, andFragrance Association, 1995), which description is incorporated hereinby reference. Particularly suitable cationic polymers for use in thecomposition include polysaccharide polymers, such as cationic cellulosederivatives, cationic starch derivatives, and cationic guars.

Examples of cationic cellulose polymers are those available fromAmerchol Corp. (Edison, N.J.,) in their POLYMER JR and LR series ofpolymers, as salts of hydroxyethyl cellulose reacted with trimethylammonium substituted epoxide, referred to in the industry (CTFA) asPolyquaternium 10. Another type of cationic cellulose includes thepolymeric quaternary ammonium salts of hydroxyethyl cellulose treatedwith lauryl dimethyl ammonium-substituted epoxide, referred to in theindustry (CTFA) as Polyquaternium 24. These materials are available fromAmerchol Corp. (Edison, N.J.,) under the trade name Polymer LM-200.

An especially preferred cationic polymer is cationic guar gumderivatives, such as guar hydroxypropyltrimonium chloride, specificexamples of which include the JAGUAR series commercially available fromRhodia Corporation (e.g., JAGUAR EXCEL or JAGUAR C13S). Other suitablecationic polymers include quaternary nitrogen-containing celluloseethers, some examples of which are described in U.S. Pat. No. 3,962,418,which description is incorporated herein by reference. Other suitablecationic polymers include copolymers of etherified cellulose, guar andstarch, some examples of which are described in U.S. Pat. No. 3,958,581,which description is incorporated herein by reference.

Non limiting examples of suitable optional synthetic cationic polymersinclude copolymers of vinyl monomers having cationic protonated amine orquaternary ammonium functionality with water soluble spacer monomerssuch as acrylamide, methacrylamide, alkyl and dialkyl acrylamides, alkyland dialkyl methacrylamides, alkyl acrylate, allyl methacrylate, vinylcaprolactone or vinyl pyrrolidone. The alkyl and dialkyl substitutedmonomers preferably have from C₁ to C₇ alkyl groups, more preferablyfrom C₁ to C₃ alkyl groups. Other suitable spacer monomers include vinylesters, vinyl alcohol (made by hydrolysis of polyvinyl acetate), maleicanhydride, propylene glycol, and ethylene glycol.

Other suitable optional synthetic polymers include vinyl compoundssubstituted with dialkylaminoalkyl acrylate, dialkylaminoalkylmethacrylate, monoalkylaminoalkyl acrylate, monoalkylaminoalkylmethacrylate, trialkyl methacryloxyalkyl ammonium salt, trialkylacryloyalyl ammonium salt, dialyl quaternary ammonium salts, and vinylquaternary ammonium monomers having cyclic cationic nitrogen-containingrings such as pyridinium, imidazolium, and quaternized pyrrolidone,e.g., alkyl vinyl imidazolium, alkyl vinyl pyridinium, alkyl vinylpyrrolidone salts. The alkyl portions of these monomers are preferablylower alkyls such as the C₁, C₂ or C₃ alkyls.

Still other suitable optional synthetic polymers for use in the shampoocomposition include copolymers of 1-vinyl-2-pyrrolidone and1-vinyl-3-methylimidazolium salt (e.g., chloride salt) (referred to inthe industry by the Cosmetic, Toiletry, and Fragrance Association,“CTFA”, as Polyquaternium-16), such as those commercially available fromBASF Wyandotte Corp. (Parsippany, N.J., U.S.A) under the LUVIQUATtradename (e.g., LUVIQUAT FC 370); copolymers of 1-vinyl-2-pyrrolidoneand dimethylaminoethyl methacrylate (refereed to in the industry by CTFAas Polyquaternium-11) such as those commercially available from ISPCorporation (Wayne, N.J., U.S.A.) under the GAFQUAT tradename (e.g.,GAFQUAT 755N); cationic diallyl quaternary ammonium-containing polymers,including, for example, dimethyidiallylammonium chloride homopolymer andcopolymers of acrylamide and dimethyldiallylammonium chloride, referredto in the industry (CTFA) as Polyquaternium 6 and Polyquaternium 7,respectively; and mineral acid salts of amino-alkyl esters ofhomopolymers and copolymers of unsaturated carboxylic acids having from3 to 5 carbon atoms.

Thickening and Suspending Agents

The compositions of the present invention preferably further incorporatethickening/suspending agents to ensure that insoluble materials arestable. A variety of materials can be employed. These include swellingand associative polymers, finely divided crystalline or amorphousinorganic and organic materials that form networks, electrolytes andcombinations thereof.

Organic polymers include carboxyvinyl polymers such as the copolymers ofacrylic acid crosslinked with polyallylsucrose as described in U.S. Pat.No. 2,798, 053, which description is incorporated herein by reference.Examples of these polymers include CARBOPOL 934, 940, 941, and 956,available from NOVEON and the alkali swellable acrylic latex polymerssold by Rohm and Haas under the ACRYSOL or ACULYN trade names.

Other suitable suspending agents include xanthan gum at concentrationsranging from about 0.3% to about 3%, preferably from about 0.4% to about1.2%, by weight of the compositions.

Other suitable polymeric suspending agents may be used in thecompositions, including those that can impart a gel-like viscosity tothe composition, such as water soluble or colloidally water solublepolymers like cellulose ethers (e.g., methylcellulose, hyd roxybutylmethylcellulose, hyd ropylcellulose, hyd roxypropyl methylcellu lose,hydroxyethyl ethylcellulose and hydroxyethylcellulose), guar gum,polyvinyl alcohol, polyvinyl pyrrolidone, hydroxypropyl guar gum, starchand starch derivatives, and other thickeners, viscosity modifiers,gelling agents, etc. Mixtures of these materials can also be used.

Optional crystalline organic suspending agents include acyl derivatives,long chain amine oxides, or combinations thereof, concentrations ofwhich range from about 0.1% to about 5%, preferably from about 0.5% toabout 3%, by weight of the shampoo compositions. When used in theshampoo compositions, these suspending agents are present in crystallineform. These suspending agents are described in U.S. Pat. No. 4,741,855,which description is incorporated herein by reference. These suspendingagents include ethylene glycol esters of fatty acids preferably havingfrom about 16 to about 22 carbon atoms. Examples include ethylene glycolstearates, both mono and distearate, but particularly distearatescontaining less than about 7% of the mono stearate. Other suitablesuspending agents include alkanol amides of fatty acids, preferablyhaving from about 16 to about 22 carbon atoms, more preferably about 16to 18 carbon atoms, preferred examples of which include stearicmonoethanolamide, stearic diethanolamide, stearic monoisopropanolamideand stearic monoethanolamide stearate. Other long chain acyl derivativesinclude long chain esters of long chain fatty acids (e.g., stearylstearate, cetyl palmitate, etc.); glyceryl esters (e.g., glyceryldistearate) and long chain esters of long chain alkanol amides (e.g.,stearamide diethanolamide distearate, stearamide monoethanolamidestearate). Long chain acyl derivatives, ethylene glycol esters of longchain carboxylic acids, long chain amine oxides, and alkanol amides oflong chain carboxylic acids in addition to the preferred materialslisted above may be used as suspending agents. For example, it iscontemplated that suspending agents with long chain hydrocarbyls havingC₈-C₂₂ chains may be used.

Examples of suitable long chain amine oxides for use as suspendingagents include alkyl (C₁₆ -C₂₂) dimethyl amine oxides, e.g., stearyldimethyl amine oxide.

Another useful crystalline suspending agent is trihydroxystearin soldunder the trade name THIXCIN R.

Network forming inorganic materials include but are not limited toclays, and silicas. Examples of clays include smectite clay selectedfrom the group consisting of bentonite and hectorite and mixturesthereof. Synthetic hectorite (laponite) clay are often used with anelectrolyte salt capable of causing the clay to thicken (alkali andalkaline earth salts such as halides, ammonium salts and sulfates).Bentonite is a colloidal aluminum clay sulfate. Examples of silicainclude amorphous silica and include fumed silica and precipitatedsilica and mixtures thereof.

Associative polymers are those which incorporate hydrophobic groupswhich can form labile crosslinks alone or with the participation ofsurfactant micelles. An example of associative polymers thehydrophobically modified cross linked polyacrylates sold by NOVEON underthe PEMULEN trade name. Other examples are hydrophobically modifiedcellulose ether and hydrophobically modified polyurethane.

A particularly preferred class of thickening and suspending agent in thepresent invention is hydrophobically modified water-soluble nonionicpolyol. Suitable hydrophobically modified water-soluble nonionic polyolsfor use herein are PEG 120 methyl glucoside dioleate (available fromAmercol under the trade name GLUCAMATE DOE 120), PEG-150 pentaerythrityltetrastearate (available from Croda under the trade name CROTHIX, PEG-75dioleate (available from Kessco under the trade name PEG-4000 DIOLEATE)and PEG-150 distearate (available from Witco under the trade nameWITCONAL L32).

Long chain fatty esters of polyethylene glycol, e.g., PEG-150distearate, are especially preferred thickening and suspending agents inthe present invention. Although the PEG fatty esters can be used alone,it has been found that their effectiveness and efficiency can be greatlyimproved when they are combined with certain electrolytes. Especiallypreferred electrolytes for use in combination PEG-150 distearate, aresodium citrate and sodium chloride as they provide a synergisticthickening system that allows adequate thickening at low levels ofinclusion in composition that have a low total concentration ofsurfactant, e.g., less than about 15 wt. %.

The above thickening and structuring agents can be used alone or inmixtures and may be present in an amount from about 0.1 wt. % to about10 wt. % of the composition.

Storage Stabilizer Agents

In addition to sulfosuccinic acid, it has been found that electrolytesthat provide certain soluble cations can also improve stability of thesulfosuccinate surfactant/amphoteric surfactant mixtures during hightemperature storage. Addition of these electrolytes also helps preventan unacceptable increase in the viscosity of compositions duringstorage, which appears to be an unusual property of sulfosuccinate andamphoteric surfactant mixtures. Such electrolytes are useful optionalingredients in the present invention.

Preferred electrolytes to be employed in the present invention are thosewhich are fully dissociated in the liquid and whose constituent ions arecompletely dissolved. Thus, preferred electrolytes do not precipitate asdifferent species with other components of the composition.

Preferred electrolytes are those that are highly soluble in thecompositions of the invention and are the most efficient in the deliveryof the required cations, and do not themselves have an adverse effect onthe mildness, pH or solubility of other formulation ingredients.

Especially preferred are water-soluble salts monovalent inorganic ions,especially ammonium, sodium, and to a lesser extent potassium salts.These include the chlorides, sulfates, carbonates and various salts ofweak organic acids such as citrates, glycolates, succinates andacrylate/polyacrylate salts and mixtures thereof.

The anions of the electrolyte should preferably themselves not be asurfactant molecule capable of micellization in water at the levelsemployed in the composition as this greatly reduces their availabilityin solution. Thus, if the anion is an organic molecule, it shouldpreferably not have an unsubstituted hydrocarbon chain greater thanabout 5 carbon atoms.

Ammonium and sodium chloride, citrate and polyacrylate and theirmixtures are the most preferred.

The exact level of electrolyte required to maintain the viscosity of thecomposition at its initial value (in the sense discussed above) dependsupon the constituents of the composition and their levels. Inparticular, the level of cation depends upon the total weight percent ofthe sulfosuccinate surfactant used in the composition. The level ofelectrolyte should be greater than or equal to about 1% by weight ofcomposition, preferably at least about 1.5% and most preferably at leastabout 2%.

Aesthetic and Adjunct Ingredients

A wide variety of optional ingredients can be incorporated in theformulation provided they do not interfere with the mildness and hairconditioning benefits provided by the composition. These include but arenot limited to: perfumes; pearlizing and opacifying agents such ashigher fatty acids and alcohols, ethoxylated fatty acids, solid esters,nacreous “interference pigments” such as TiO2 coated micas; dyes andpigment coloring agents; sensates such as menthol; preservativesincluding anti-oxidants and chelating agents; emulsion stabilizers;auxiliary thickeners; and mixtures thereof.

Additional Hair and Skin Benefit Agents

A variety of optional ingredients can be incorporated into thecompositions of the instant invention to promote hair and scalp health.However, these ingredients should be chosen to be consistent with themildness of the composition. Potential benefit agents include but arenot limited to: lipids such as cholesterol, ceramides, andpseudoceramides; additional non-silicone hair conditioning agents suchas synthetic or natural hydrocarbon esters and waxes; humectants such asglycerol and sorbitol; antimicrobial agents such as zinc pyridinethioneand TRICLOSAN; sunscreens such as cinnamates and mixtures thereof.

Evaluation Methodology

Formulation Viscosity Protocol

Shampoo samples contained in 6 oz glass jars were placed in a water bathset at 26.7° C. After 1 day of storage at 26.7° C., the shampoo sampleswere removed and their viscosity was immediately measured using aBrookfield viscometer fitted with an RV4 spindle at a rotational speedof 20 rpm. The spindle was allowed to rotate at 20 rpm for 1 minutebefore the viscosity measurements were recorded.

Storage Stability Testing Protocol

Shampoo samples were placed in 6 oz jars and labeled with the amount oftime each was to be kept in storage. The jars of shampoo were placed inan oven set to the required storage temperature, e.g., 49° C. Once thestorage time for each jar had been reached, the jars were taken out ofstorage and the viscosity of the stored shampoo samples were measuredusing the Formulation Viscosity Protocol described above.

Zein Solubility In-Vitro Assay

Zein solubility provides a simple directional indication of mildness andis widely used in the art for testing the mildness of both surfactantraw materials, shampoos and skin cleansing compositions. Zein is aprotein (blends of amino acid derived from maize) which swells anddenatures in response to surfactants in a similar way to skin keratinproteins. This procedure was developed on the basis that the more Zeinsolubilized by a given surfactant composition under standardized testconditions, the greater is the irritancy of the composition. Zeinsolubility is not intended as a replacement for clinical studies or themore biologically based Fluorescein Leakage In-Vitro Assay even though areasonable correlation has been demonstrated. Therefore the principleapplication for Zein solubility is for initial screening where itprovides a good predictor of eventual irritation potential. Under thetest conditions employed and described below a Zein solubility of lessthan 1% is a good indicator of potentially mild compositions while aZein solubility greater than 1% is a good indication that thecomposition will be irritating to the eyes.

Apparatus

Analytical balance, 100 ml beakers, stir bars, medium stir plate, 10 mlsyringe, 20 ml scintillation vials, conventional oven, set at 75° C.

Procedure

1. Weigh 6.25 g of shampoo into a 100-ml beaker and dilute it to 50 gwith Dl water.

2. Mix the solution on a stir plate @ 300 rpm (set dial at 4 on stirringplate) until the solution looks uniform or the entire sample isdissolved.

3. Record the pH of the solution.

4. Withdraw 6 ml of solution using a syringe.

5. Filter solution through a 0.45-micron syringe filter onto ascintillation vial.

6. Cap the vial and label it as blank. A blank is needed to correct forany soluble material.

7. Add 2 g of Zein to the remaining solution and equilibrate for 1 hourat constant stirring speed (300 rpm). After 10 minutes of stirring, ifall or most of the Zein dissolved, add an additional 1 g of Zein. Keepadding more Zein in 1 g increments every 5-10 minutes until there isundissolved Zein floating in the solution.

8. After 1 hour of constant stirring, allow solution to settle for 5minutes.

9. Withdraw 6 ml of the supernatant solution using a syringe and filterit through a 0.45 micron syringe filter onto a scintillation vial.

10. Cap the vial and label it as sample.

11. Perform nonvolatile on both samples using a conventional oven set at75° C. Allow samples to dry overnight.

12. Calculate the percent Zein dissolved.

Calculation

% Zein solubilized=% nonvolatile of sample−% nonvolatile of blank

Subjective Lather Assessment Panel

The overall lather of test shampoo compositions was assessedsubjectively by a naive panel composed of at least 10 participantsemploying tresses of hair. The test protocol was as follows:

1) Adjust water temperature to 40° C.

2) First wet hands and hair tresses (4 gm tresses of hair)

3) Apply 0.5 ml of shampoo (premeasured in syringe)

4) Massage hair tresses for 1 minute to evaluate lather.

5) Rinse tresses thoroughly, and then repeat above steps for nextshampoo sample.

6) After treating the tresses with all four shampoos, rank the lather ofeach shampoos from best lather (4) to worst lather (1).

Note: Order of samples given to participants was randomized for eachparticipant.

EXAMPLES

The following examples are shown as illustrations of the invention andare not intended in any way to limit its scope.

Example 1

This example illustrates the criticality of the ratio of sulfosuccinicacid to sulfosuccinate surfactant on storage stability.

Examples Ex 1A through Ex 1H, whose compositions are given in Table 1were prepared as follows by the combination of the premixes describedbelow:

A. Premix Preparation

Carbomer 980 Premix (A) as required: This premix is formed by dissolvingCarbomer 980 in water at room temperature and mixing until completelyhydrated and dissolved (no lumps of “fisheyes”).

Jaguar C13S Premix (B) (or other cationic polymer) is prepared by mixingJaguar C13S in propylene glycol for 10 minutes or until completelydissolved and uniform.

Ammonium Chloride(or NaCl)/Sodium Citrate Dihydrate 25 wt. % Premix (C)is prepared by adding ammonium chloride (or sodium chloride) and sodiumcitrate dihydrate to water and mixing until completely dissolved.

PEG-150 Distearate (5 wt. %) Premix (D) is prepared by addition to aportion of the CAPB (or other amphoteric surfactant) solution heated to65° C. The mixture is cooled to room temperature and additional wateradded as required.

B. Main Batch Preparation:

Water is added to the mixer followed by the addition of the CarbomerPremix (A). Under mixing optional surfactants such as Sodium LaurethSulfate are added as required (e.g., SLES-1, 70%) and mixed untildispersed. The Jaguar C13s Premix (B) is then added and the batch ismixed at 100 rpm 30 minutes. Disodium Laureth Sulfosuccinate is thenadded and dispersed followed by the addition of the remainingamphoteric. Pearlizer, silicone, preservatives and sodium hydroxide arethen added and dispersed. This is followed by the Ammonium Chloride(orNaCl)/Sodium Citrate Dihydrate Premix (C). The viscosity and pH are thenmeasured and adjusted with additional salt, ppg-9, or PEG-150DS Premix(D) and NaOH or Citric Acid respectively. TABLE 1 Compositions andPhysical Properties of Example 1 Ingredients Ex 1A Ex 1B Ex 1C Ex 1D Ex1E Ex 1F Ex 1F Lauryl ethoxy sulfate (1EO) 6 6 6 6 6 6 6 Disodiumlaureth 4 4 4 4 4 4 4 sulfosuccinate Cocoamidopropyl betaine 3 3 3 3 3 33 Sulfosuccinic acid 0.163 0.238 0.46 0.56 0.6 0.625 0.687 Carbopol(Carbomer 980) 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Silicone Emulsion (Silicone1.5 1.5 1.5 1.5 1.5 1.5 1.5 Gum/ Amodimethicone blend PCP2056S) CationicGuar (Jaguar 0.2 0.2 0.2 0.2 0.2 0.2 0.2 C13S) Pearlizer (Mirasheen 6.56.5 6.5 6.5 6.5 6.5 6.5 CP920; Rhodia) Ammonium chloride 2.0 2.0 2.0 2.02.0 2.0 2.0 Sodium Citrate 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Minors fragrance,0.22 0.22 0.22 0.22 0.22 0.22 0.22 preservatives, dyes Water to 100 to100 to 100 to 100 to 100 to 100 to 100 pH (adjusted with NaOH) 6.3 6.36.3 6.3 6.3 6.3 6.3 Sulfosuccinic acid level as a 4.1 5.9 11.5 14.0 15.015.6 17.2 % of sulfosuccinate surfactant Initial Viscosity (cps) 62005700 5500 4300 5200 4000 5000 Final Viscosity after 11 10800 9500 82006500 6700 6000 7000 weeks at 49° C. Viscosity Increase after 11 46003800 2700 2200 1500 2000 2000 weeks storage @ 49° C. % Increase inviscosity after 74% 67% 49% 51% 29% 50% 40% storage from initial value

The initial viscosity of the example compositions and the change inviscosity after storage are also recorded at the bottom of Table 1together with the % sulfosuccinic acid relative to the sulfosuccinatesurfactant.

It is seen that the level of sulfosuccinic acid has a much greatereffect in preventing the viscosity of compositions stored at an elevatedtemperature from increasing than it has on the initial viscosity of thecomposition. In fact, the viscosity of the compositions stored at roomtemperature for the same period of time hardly changes from its initialvalue (not shown). Thus, sulfosuccinic acid is not acting as a typicalviscosity regulator in the conventional sense but rather as a highlyspecific storage stabilizing agent, especially storage at elevatedtemperature.

Storage at an elevated temperature is widely used as an accelerated testof storage stability at ambient conditions, i.e., shelf-life. Anincrease in viscosity of less than about 75% of the initial value isstill acceptable in compositions having an initial viscosity of about5000-7000 CPS, i.e., the compositions of Table 1. It is noted from Table1 that a level of at least about 4% sulfosuccinic acid relative to thesulfoccinate surfactant is required in the composition to maintain theviscosity after storage below this threshold.

Example 2

This examples demonstrates that the combination of the sulfosuccinateand amphoteric surfactants produces the increase in viscosity.

Example Ex 2A and EX 2B and comparative examples C2A-C2D whosecompositions are given in Table 2, were prepared according to themethods described in Example 1. TABLE 2 Compositions and PhysicalProperties for Example 2 Wt. % Ingredients Ex2A Ex2B C2A C2B C2C Laurylethoxy sulfate (1EO) 6 6 6 6 6 Disodium laureth sulfosuccinate 4 4 4 4Cocoamidopropyl betaine 3 3 3 Sulfosuccinic acid 0.163 0.46 0.163 0.46 0Silicone/Aminosilicone blend 1.5 1.5 1.5 1.5 1.5 Cationic Guar (JaguarC13S) 0.2 0.2 0.2 0.2 0.2 Pearlizer (Mirasheen CP920; Rhodia) 6.5 6.56.5 6.5 6.5 Carbopol (Carbomer 980) 0.4 0.4 0.4 0.4 0.4 Ammoniumchloride 2.0 2.0 2.0 2.0 2.0 Minors, fragrance, 0.22 0.22 0.22 0.22 0.22preservatives, dyes Water to 100 to 100 to 100 to 100 to 100 pH(adjusted with NaOH) 6.3 6.3 6.3 6.3 6.3 Sulfosuccinic acid level as a4.1 11.5 4.1 14.1 0 % of sulfosuccinate Viscosity Increase after 11weeks 4,600 2,700 1,488^(a) 704^(a) −406^(a) storage @ 49° C.^(a)Extrapolated values based on 4 week storage data @ 49° C.

The change in viscosity after accelerated storage (11 weeks @ 49° C.)are recorded at the bottom of Table 2 together with the % sulfosuccinicacid relative to the sulfosuccinate surfactant. Several points arenoteworthy.

Most surprisingly, the largest increases in viscosity after acceleratedstorage only occurs in compositions that contain both the sulfosuccinatesurfactant and the amphoteric surfactant—in this case a betaine (compareEx 2A and Ex 2B with C2A-C2C). Furthermore, it is in such combinationswhere the level of sulfosuccinic acid is critical (compare viscosityafter storage of Ex 2A with Ex 2B).

In contrast, compositions that do not contain the amphoteric and thesulfosuccinate surfactant do not exhibit such large increases inviscosity after storage and their viscosity does not respond tosulfosuccinate level (compare viscosity after storage of comparativeexamples C2A-C2C). Thus, sulfosuccinic acid is not acting as a typical“generic” viscosity regulator and its action is highly specific to thesulfosuccinate surfactant/amphoteric surfactant compositions disclosedherein.

Example 3

This example illustrates the effect on mildness and lather of combininga sulfosuccinate surfactant with an amphoteric surfactant.

Example Ex 3 and comparative examples C3A-C3C whose compositions aregiven in Table 3, were prepared by the methods described in Example 1.TABLE 3 Compositions and Physical Properties for Example 3 C3AIngredients Ex 3 Wt. % C3B C3C Lauryl ethoxy sulfate (1EO) 6 13 6Disodium laureth sulfosuccinate 4 13 7 Cocoamidopropyl betaine 3Sulfosuccinic acid 0.56 1.8 0.56 0.98 Silicone Emulsion (Silicone Gum/1.5 1.5 1.5 1.5 Amodimethicone blend PCP2056S) Cationic Guar (JaguarC13S) 0.2 0.2 0.2 0.2 Pearlizer (Mirasheen CP920; 6.5 6.5 6.5 6.5Rhodia) Ammonium chloride 2 2 2 2 Minors fragrance, preservatives, 0.220.22 0.22 0.22 dyes Water to 100 to 100 to 100 to 100 pH (adjusted withNaOH) 6.3 6.3 6.3 6.3 Sulfosuccinic acid level as a % of 14.0 14.0 014.0 sulfosuccinate Average Lather Score 3.2 1.4 3.4 2.0 In-VitroMildness (zein solubility) 1.8 2.1 3.07 2.41

The Average Lather Score (as measured by the Subjective LatherAssessment Panel described above in the METHODOLOGY SECTION), and thein-vitro mildness (as measured by the Zein Solubility Test alsodescribed above in the METHODOLOGY SECTION) are recorded at the bottomof Table 3.

It is clear from the results that of all the surfactant combinationstested, the combination of an alkyl ethoxy sulfate, a sulfosuccinatesurfactant and an amphoteric surfactant (Ex 3) has the lowest Zeinsolubility and thus should be mildest. Furthermore, this combination hasexcellent lather and thus does not sacrifice in-use properties andefficiency for mildness (compare Ex 3 with C3B).

This example thus demonstrates the desirability of combinations ofsulfosuccinate surfactant and amphoteric surfactant for cleansing humanhair and skin and the relevance of solving the storage stabilityproblems intrinsic in such combinations.

Based on mildness (Zein solubility) and lather performance, aparticularly preferred embodiment of the invention is a compositionconsisting essentially of: Disodium laureth sulfosuccinate 2%-6%Cocoamidopropyl betaine 2%-5% Lauryl ethoxy sulfate (1-3 EO) 5%-9%Sulfosuccinic acid 4%-20% (based on the sulfosuccinate surfactant)

that provides a Zein solubility of less than or equal to 2 measured bythe Zein Solubility Test, and Average Lather Score of at least 3measured by the Subjective Lather Assessment Panel.

The term “consisting essentially of” as used in the present context,means that various optional ingredients can be included so long as theydo not compromise (i.e., reduce) the mildness and lather performance ofthe composition below the threshold values defined above. Usefuloptional ingredients include: Ammonium chloride and/or sodium chloride0%-2.5% Sodium citrate 0%-2% Cationic polymer 0%-1% Silicone 0%-5%Thickener 0%-10% Aesthetic adjuvants 0%-5% (color, perfume, biocidesetc.)

Examples 4-6 are meant to illustrate some of the varied compositionsuseful in the instant invention but are in no way meant to limit thescope of sensory additives, adjuncts and benefit agents that can beemployed.

Example 4

The compositions in Table 4 illustrate different surfactant systems ofthe invention. TABLE 4 Example of Different Surfactant Systems ofInvention Wt. % Ingredients Ex 4A Ex 4B Ex 4C Ex 4D Ex 4E Ex 4F Ex 4G Ex4H Sodium Laureth Sulfate (1EO) 6.0 10.0 5.0 7.0 5.0 6.0 Sodium LaurethSulfate (2EO) 8.0 Disodium Laureth 4.0 6.7 10.0 2.0 4.0 4.0 5.0 4.0Sulfosuccinate Cocamidopropyl Betaine 3.0 5.0 7.5 3.0 2.0 2.0Hydroxysultaine 3.0 2.0 Lauroamphoacetate 3.0 1.0 Carbopol 980 0.40 0.400.40 0.40 0.40 0.40 0.40 0.40 Jaguar C13S 0.10 0.10 0.10 0.10 0.10 0.100.10 0.10 Polyox WSR308 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025Methocel 40-0202 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Glycerine 1.000 1.0001.000 1.000 1.000 1.000 1.000 1.000 L-Lysine Hydrochloride 0.010 0.0100.010 0.010 0.010 0.010 0.010 0.010 Silk Amino acids 0.010 0.010 0.0100.010 0.010 0.010 0.010 0.010 Borage Extract 0.001 0.001 0.001 0.0010.001 0.001 0.001 0.001 Mirasheen CP920; Rhodia 6.50 6.50 6.50 6.50 6.506.50 6.50 6.50 DC1788 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 SME2530.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 Perfume 0.80 0.80 0.80 0.80 0.800.80 0.80 0.80 DMDM Hydantoin 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10Kathon CG 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Versene 100 0.20 0.200.20 0.20 0.20 0.20 0.20 0.20 NaOH, 50% 0.40 0.40 0.40 0.40 0.40 0.400.40 0.40 Sulfosuccinic acid 0.18 0.335 0.65 0.08 0.2 0.4 0.3 0.18 NH₄Cl2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 PPG-9 0.35 0.35 0.35 0.35 0.350.35 0.35 0.35 Soft Water To To To To To To To To 100% 100% 100% 100%100% 100% 100% 100%

Example 5

The compositions in Table 5 illustrate different conditioning systems ofthe invention. TABLE 5 Example of Different Conditioning Systems ofInvention Wt. % Ingredients Ex 5A Ex 5B Ex 5C Ex 5D Ex 5E Ex 5F Ex 5GCarbopol 980 0.40 0.40 0.4 0.40 0.40 0.40 0.40 Sodium Laureth Sulfate(1EO) 6.0 6.0 6.0 6.0 6.0 6.0 6.0 Disodium Laureth Sulfosuccinate 4.04.0 4.0 4.0 4.0 4.0 4.0 Cocamidopropyl Betaine 3.0 3.0 3.0 3.0 3.0 3.03.0 Jaguar C13S 0.10 0.20 0.20 0.20 0.20 0.20 0.20 Polyox WSR308 0.0250.025 Methocel 40-0202 0.3 0.3 Polyox WSR-N-60K 0.025 Mirasheen CP920;Rhodia 6.50 6.50 6.50 6.50 6.50 6.50 6.50 DC1788 0.65 1.30 SME253 0.100.20 0.20 0.20 0.20 0.20 0.20 DC7036 — 1.30 — 1.30 1.30 1.30 1.30Glycerine 1.000 1.000 1.000 1.000 1.000 1.000 1.000 Perfume 0.80 0.800.80 0.80 0.80 0.80 0.80 DMDM Hydantoin 0.10 0.10 0.10 0.10 0.10 0.100.10 Kathon CG 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Versene 100 0.20 0.200.20 0.20 0.20 0.20 0.20 NaOH, 50% 0.40 0.40 0.40 0.40 0.40 0.40 0.40Sulfosuccinic acid 0.16 0.2 0.28 0.18 0.24 0.16 0.4 NH₄Cl 2.00 1.5 2.001.5 1.4 2.00 1.00 NaCl 0.6 0.8 0.3 1.0 Sodium citrate 0.25 1.0 0.6 PPG-90.60 0.35 0.20 0.35 0.35 0.35 0.35 Soft Water To To To To To To To 100%100% 100% 100% 100% 100% 100%

Example 6

The compositions in Table 6 illustrate different benefit agents of theinvention. TABLE 6 Example of Different Benefit Agents of Invention Wt.% Ingredients Ex 6A Ex 6B Ex 6C Carbopol 980 0.40 0.40 0.40 SodiumLaureth Sulfate (1EO) 6.0 6.0 6.0 Disodium Laureth Sulfosuccinate 4.04.0 4.0 Cocamidopropyl Betaine 3.0 3.0 3.0 Jaguar C13S 0.20 0.20 0.20Polyox WSR308 0.025 0.025 0.025 Methocel 40-0202 0.3 0.3 0.3 Glycerine1.000 1.000 1.000 L-Lysine Hydrochloride 0.010 0.010 Silk Amino acids0.010 0.010 Borage Extract 0.001 Mirasheen CP920; Rhodia 6.50 6.50 6.50SME253 0.20 0.20 0.20 DC7036 1.30 1.30 1.30 Perfume 0.80 0.80 0.80 DMDMHydantoin 0.10 0.10 0.10 Kathon CG 0.04 0.04 0.04 Versene 100 0.20 0.200.20 NaOH, 50% 0.40 0.40 0.40 NH4Cl 2.1 1.6 2.00 Sodium citrate 0.75 0.2PPG-9 0.35 0.35 0.35 Soft Water To 100% To 100% To 100%

1. A mild aqueous composition suitable for cleansing hair and skincomprising: i) from about 1% to about 20% of a sulfosuccinatesurfactant, ii) from about 1% to about 20% of an amphoteric surfactant,and iii) sulfosuccinic acid or a salt of sulfosuccinic acid, wherein thesulfosuccinic acid or the salt of sulfosuccinic acid is present in anamount of at least about 4% based on the weight of the sulfosuccinatesurfactant.
 2. The composition according to claim 1, wherein thesulfosuccinate surfactant is a C₁₀-C₁₄ alkyl or a C₁₀-C₁₄ alkyl ethoxy(1-4 EO) sulfosuccinate.
 3. The composition according to claim 1,wherein the amphoteric surfactant is selected from the group consistingof betaine, amphoacetate, hydroxy sultaine, amine oxide and mixturesthereof.
 4. The composition according to claim 3, wherein the betaine isa C₁₀- C₁₈ alkyl betaine or an C₁₀-C₁₈ alkylamidopropyl betaine, ormixtures thereof.
 5. The composition according to claim 1, wherein thesalt of succinic acid is a sodium, ammonium or alkanolammoniumsulfosuccinate.
 6. The composition according to claim 1, wherein thesulfosuccinic acid or salt of sulfosuccinic acid is present in an amountgreater than about 6% based on the weight of the sulfosuccinatesurfactant.
 7. The composition according to claim 1, further comprisinga C₁₀-C₂₂ alkyl ethoxy sulfate surfactant having 1 to about 5 ethyleneoxide groups.
 8. The composition according to claim 8, wherein theweight ratio of the alkyl ethoxy sulfate surfactant to thesulfosuccinate surfactant is in the range from about 2:1 to about 1:1.9. The composition according to claim 1, further comprising one or moreammonium or sodium salts or mixtures thereof at a level of at least 1.5%based on the total weight of the composition.
 10. The compositionaccording to claim 1, further comprising a silicone.
 11. The compositionaccording to claim 10, wherein the silicone is selected from the groupconsisting of a volatile or non-volatile organo silicone, an aminofunctional organo silicone, an amino functional organo siliconepolyether copolymer and mixtures thereof
 12. The composition accordingto claim 1, further comprising a cationic polymer.
 13. The compositionaccording to claim 12 wherein the cationic polymer is a cationicallymodified polysaccharide selected from the group consisting of acationically modified starch, a cationically modified cellulose, acationically modified guar and mixtures thereof.
 14. The compositionaccording to claim 1 wherein said composition has a pH between about 5and about 7 and an acid buffer capacity of at least 0.02 moles acid perliter of composition.